Dependability and performance analysis of redundant DSAS architectures using FEH and MRM

Digital substation (DS) is an integral part of the smart grid migration plan. Availability/reliability of DS has been evaluated using traditional approaches. Although many new methods have been proposed, there is no standard approach exist till date. Due to evolving cyber-physical nature of Digital Substation Automation System (DSAS), this paper investigates the effect of inclusion of Fault/Error Handling Model (FEH) on the availability of three redundant DSAS architectures by comparing it with the conventional Reliability Block Diagram (RBD) models. The paper also discusses the need to include Markov reward process (MRP) based performance model into dependability analysis of DSAS and demonstrates its effect on the dependability of DSAS through both, analytical and simulation methods.